202hw2_KEY - Biology 202 Homework 2 Due: 9/11 or 9/12; in...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Biology 202 Homework 2 Due: 9/11 or 9/12; in discussion Please type (not hand-write) ONLY the answers to question onto the question sheet itself (this sheet). Please highlight or otherwise indicate the parts that you have typed with italics , underlining or bold ing. All of these questions require additional working. The work done to answer the questions should not be on this sheet but instead attached to the back as supplemental pages. You must include all of your work pages. The supplemental work pages do not need to be typed 1. Two true breeding plants with different sized flowers were crossed. One of the parents had flowers that were 8 cm in diameter and the other parent had flowers that were 16 cm in diameter. The F 1 progeny had flowers that were 12 cm in diameter. a) If we self-fertilize the F 1 progeny, what would be the phenotype ratios in the F 2 if the trait (flower size) is controlled by a single gene and incompletely dominant alleles? DD = homozygote parent, flowers with 16 cm diameter Dd = heterozygote progeny, flowers with 12 cm diameter dd = homozygote parent, flowers with 8 cm diameter The F 1 progeny will all be heterozyotes (Dd genotype) The F 2 progeny would have genotype ratios of 1:2:1 (one DD, two Dd, one dd) and also phenotype ratios of 1:2:1 (one 16 cm, two 12 cm, one 8 cm). *** 1 point b) How would the distribution of phenotypes be different in the F 2 if the trait was controlled by multiple genes? If the trait was controlled by multiple genes (an example of polygenic inheritance), then the range of phenotypic variation would expand, meaning that there would be more intermediate flower diameters between 8 cm and 16 cm. *** 1 point
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 4

202hw2_KEY - Biology 202 Homework 2 Due: 9/11 or 9/12; in...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online